Place three bowls of water on the table.
One with ice cold water, one with very warm water, one at room temperature, at the center.
Place hands at the end bowls for a while.
Then, immediately place both hands in the center bowl.
The water feels very warm to the touch of the colder hand and vice versa.
When in the hot and cold bowls,
your hands first resisted the danger with pain,
then survived it easily with denial,
which they took with them to the center bowl.
It is imperative that we develop such automatic systems
in the brain if we are to adapt to the environment
enough to survive.
Pain is essential for survival, yet destructive if suffered unnecessarily.
Any form of pain must have a denial mechanism to defend it,
if the pain mechanism itself is to survive.
The subconscious human mind is composed of many
such mechanisms all operating
independently,
each developed over the long course of evolution
of the brain, and is separately guided by survival,
just like any other organ or mental power in
animals.